Improved furnace for smelting zinc



8, BOYDEN.

Making Spelter. v \No. 6,180. Patented Man lfa I849 l I I UNITED STATESPATENT OFFICE.

SETH .BOYDEN, OF NEWVARK, NEW JERSEY.

IMPROVED FURNACE FOR SMELTING ZINC.

Specification forming part of Letters Patent No. 6,180, dated March 13,1849.

To all whom it may concern.-

Be it known that I, SETH BOYDEN, of Newark, in the county of Essex andState of New Jersey, have invented a new and useful Mode of ConstructingFurnaces and Retorts for Smelting Zinc Ore; and I do hereby declare thatthe following is a full and exact descrip tion.

The nature of my invention consists in a double retort surrounding thefire with the ore, so that the heat has but little chance to escape,except through the ore orobject to be heated.

To enable others skilled in the art of reducing zinc ore to fullyunderstand the nature of my invention, I will proceed to describe itsconstruction and operation.

The retorts or furnace may be made of fireclay, like glass-furnace pots,or laid up with fire-bricks or any of the known fire materials, and ofany dimensions desired. A convenient form for theinner retort is a coneproportioned thus: the base-line two and elevation three, the sidessomewhat arched or inclined to a hemisphere. This retort is placed onbrickwork, itsopen broad end down. The fire-grates are placed in thecenter just below the base, with an ascending passage on opposite sidesto supply the fuel; also, a flue on each side of the grates for thesmoke and blast to pass off under the edge of the retort. The secondretort is larger, and its proportion is-the base one and elevation two,arched on the side like the first, with the apex removed, and a holethrough the top. This is placed over the former retort, resting on thesame line of brick-work, closing the bottom and forming the ore-chamberbetween the outside of the inner retort and inside of the outer retort.This compound or double retort is inclosed (except the top) in a case orbrick-work, forming a hot-air chamber between the outside retort andcase. The fines from the fire conduct the hot air to this chamber.through four fines at the bottom. These flues also lead to four'holes inthe bottom of the ore-chamber to discharge the remains aftersublimation.

The annexed drawings are representations of the model accompanying thisspecification.

It then passes away from the furnace Figure 1 is a statue or externalview of the furnace. The outside retort, projecting out of the case, isrepresented at A. The out side case of the furnace is represented at B.The base or bottom on which the retorts are placed is represented at O0. Two of the four flues through which the smoke and blast leave thefurnace, and the remains after dis-' The outside case surrounding theretorts is represented at G G. The hot-air chamber is represented at HH. The fines leading from the fire-chamber to the hot-air chamber arerepresented at I I.

The ore for distillation is prepared with its fluxes in the usual mannerand introduced through the aperture at the top into the orechamber. Thecondenser. is then attached to the aperture and the heat raised to thedegree required by lighting a fire in the chamber and directing acurrent of air under the grates, and continued until the metallic zinchas sublimed and passed into the condenser.

I do not claim to be the inventor of retorts, or rnuffles, or pots, orcylinders, or chambers, in furnaces to receive them, for distilling orvolatilizing zinc, or any of the modes now in use where the heat isgenerated in the chamber with the retorts or muffles, or generated in afire-place and pass into a chamber containing pots, cylinders, muffles,or retorts heating the sides of the furnace and flues and walls of thechamber, which serve only to confine the heat round the retorts. Theseheated walls allow much caloric to pass away without coming in contactwith the ore, and require from ten to twenty tons of coal to produce aton of metallic zinc.

hat I do claim as my invention, and desire to secure by Letters Patent,is-

A combination or double retort or furnace generating the heat within thevessel or chamber containing the ore to be heated, surroundone ton ofzinc by four and one-fourth tons of ing' the fire-chamber or place ofcombustion coal. with the ore, so that the caloric going off in anydirection from the fire (except down through SETH BOYDEN the grates)must pass through the ore. With Witnesses: this arrangement merchantablemetallic zinc F. HOLDEN,

is obtained from the ore in the proportion of WILLIAM LEE.

